CANON - Canon EF 400mm f28L USM Parts

Complete parts catalog for the Canon EF 400mm f/2.8L USM lens (ref. C21-8282), designed for maintenance technicians and optical repair specialists working with professional-grade equipment. The document contains detailed exploded-view diagrams across pages 1-4 that systematically break down each optical element, focusing mechanism, barrel assembly, mount interface, and electronic contact points throughout the lens structure. The parts list on pages 5-7 itemizes over 150 individual components, each assigned official Canon reference numbers and component classifications, with precise quantity specifications for accurate ordering and replacement. Coverage includes all optical lens groups (G1 through G10), adjustment rings, springs, electrical contacts and connectors, fasteners in various profiles, sealing gaskets, tripod foot mounts, and integrated electronic modules. A comprehensive cross-sectional optical diagram on page 9 illustrates the complete light path through the lens assembly. The catalog also documents the Canon ET-161B and ET-161B II lens hoods (refs. C44-8151 and C44-8152) with corresponding individual parts breakdowns. This service manual provides the technical reference essential for accurate component identification, sourcing, and installation during repair and maintenance operations.